In numerous applications of processing apparatus, it is necessary to orient objects in a common direction and to feed them as a high-speed stream for further mechanical manipulation and use. For this purpose, rotating feeders have been provided which rely largely on centrifugal force to orient the objects being handled. An example of apparatus requiring such feeders is found in prior U.S. Pat. No. 4,055,455 of the present inventors, which apparatus is useful in lining and testing container closures such as caps or the like. The caps or closures to be thereby processed, must be presented to this apparatus as an incoming stream wherein each cap is oriented with its open end facing in an upward direction, i.e., this is necessary in order that all appropriate functions of the lining and testing apparatus be performed. It will be evident, further, that in numerous other manufacturing operations, parts similarly must be oriented in common directions to enable a continuous stream for processing to be available.
To meet such requirements, various apparatus for orienting and feeding small parts, such as caps, lids, or the like, have been developed over the years. U.S. Pat. No. 4,214,656 of the present inventors, for example, is specifically directed at the cap orienting and feeding problem which has been described. In this patent, a construction is disclosed which enables increased dependability in cap orientation and also higher speed and feeding. These objectives are achieved by an arrangement which includes a feeder bowl which accepts the randomly oriented caps and feeds them from an output port in the bowl, as an in-line stream of caps oriented in a substantially horizontal plane. An inclined twisting chute extends from the output of the feeder bowl. This chute receives the in-line stream of caps and twists the plane of advance through 90.degree., whereby the caps are reoriented to a stream wherein the diameters are substantially in a vertical plane. A guide chute extends at an incline from the twisting chute and includes an input section for receiving the caps at the vertical orientation, an output section whereat the caps are oriented with their diameters parallel to the support surface, and a transition zone between the input and output sections, whereat the caps gravitationally tip and fall from the vertical plane to the reoriented, more nearly horizontal positions. A biasing device can be used in conjunction with this arrangement for biasing the tipping of the caps so that they fall with their open ends facing in an upward direction.
Thus, rotating feeders are well-known devices used in the art for feeding individual units from a population of such units to a processing apparatus or for discharging them in aligned relationship of such units onto a moving conveyor, or the like. Such feeders are commonly used in the pharmaceutical industry, in the bottling field, in the electronics industry, and in many other fields where individual small components in a population of such components are desired to be discharged individually and in aligned relationship.
While is has been found that no particular difficulty is experienced when dealing with components made from a relatively hard, frictionless material are involved, there has been considerably difficulty in using rotating feeder techniques for discharging items formed from soft materials which exhibit a relatively high coefficient of friction, such as materials formed from elastomeric substances, viz. rubber, artificial rubbers, various rubber-like polymers, and the like. Examples of articles which need to be individually segregated and fed from a random population, are washers formed from soft rubber or synthetic elastomeric materials. Difficulties are experienced with conventional feeders such as referred to above when attempts are made to handle such articles in them.